Fence Post Depth Calculator

At the 1/3 ratio, bury about 1.98 feet (roughly 24 inches). Total post length should be about 7.98 feet. Buy 8-foot posts or longer.

At least one-third of the total post length should be underground. For a 6-foot above-ground fence, that means roughly 2 feet of burial depth.

Use 1/3 for normal soil and moderate wind. Use 2/5 (0.40) or 1/2 (0.50) in sandy soil, high wind, or heavy solid fencing that catches more wind load.

For a 6-foot fence with a 10-inch diameter hole about 2 feet deep, plan on roughly 0.5 to 1 cubic foot of concrete per post, or 2 to 4 bags of 50-lb premix.

Extra length covers uneven ground, trimming, and setting errors. Add a few inches beyond the calculated total post length when purchasing.